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Green PCIe x1 card with four serial ports and one parallel port

CableMAX

CableMAX CM-4S1PRS232 4S1P PCIe x1 expansion card

SKU CH-59EM-5QE8E

Adds four 16C950 UART serial ports and one IEEE1284 parallel port via a PCIe x1 slot with 250Mbytes/sec throughput

  • External connectors4 x Serial Ports
  • Product typePCI Express to Serial Port Card
  • Adds four high-performance 16C950 UART serial ports for legacy device connectivity
  • Includes one IEEE1284 compliant parallel port supporting SPP/EPP/ECP modes
  • Delivers 5V or 12V power over serial connectors to simplify peripheral wiring
  • Full x1 PCI Express throughput at 250Mbytes/sec with PCIe 1.0a compliance
  • 128-byte FIFO buffers and 921.6Kbps baud rate ensure reliable high-speed data transfer

Legacy I/O expansion

The CableMAX CM-4S1PRS232 is a PCI Express x1 add-in card that adds four RS-232 serial ports and one IEEE1284 parallel port to a desktop system. It targets integrators and technicians who must connect legacy industrial equipment, point-of-sale hardware or older peripherals to modern motherboards that lack native COM and LPT headers. The card fits any standard PCIe x1 slot and operates with 5V or 3.3V signalling tolerance.

Sustained throughput

Each of the four UART channels uses a 16C950-compatible controller with 128-byte FIFO buffers per transmitter and receiver, supporting baud rates up to 921.6Kbps and automated in-band and out-of-band flow control. The PCI Express 1.0a interface delivers full x1 throughput of 250Mbytes/sec, so sustained multi-port traffic does not saturate the bus. Advanced error reporting with ECRC support helps maintain data integrity during long transfers.

Port count decides fit

The single specification that determines suitability is the combination of four serial ports plus one parallel port on a single bracket. Systems that need fewer serial channels, a different connector type or no parallel port should select an alternative card, while applications requiring more than four COM ports will need additional expansion.

How it compares

Measured against everything we stock in PCIe Expansion Cards, at today’s prices. Recalculated every night.

Price $16.99
Cheaper than about 78% of the 891 comparable items (median $30.99).

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Specifications

Product
Model nameCM-4S1PRS232
Product typePCI Express to Serial Port Card
Ports & slots
External connectors4 x Serial Ports

Questions about this item

Does the CM-4S1PRS232 run hot or draw much power when left on all day?

The card uses a single PCIe x1 slot with 250Mbytes/sec throughput and operates at 3.3V or 5V tolerance, so heat and power draw stay minimal during continuous use.

What must my PC already have for this card to work?

You need a free PCI Express x1 slot compliant with revision 1.0a and an operating system that supports Plug-and-Play serial and parallel port drivers.

Will the CM-4S1PRS232 work alongside my older RS-232C and parallel devices?

Yes — the four 16C950 UART channels are fully compatible with 16C550-type devices, support baud rates up to 921.6Kbps, and the parallel port meets IEEE1284 SPP/EPP/ECP standards.

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